Abstract: The organic efficiency, an indicator for evaluating process performance of coal gravity separation equipment specified in the national standard “GB/T 15715—2014 Performance Evaluation for Coal Gravity Separating Equipment”, is not clearly and precisely defined. To address this issue, the indicator of quality efficiency is proposed. Based on the proposed indicator and the float-and-sink analysis data and related washability curves as given in the attachment of the above-mentioned standard, obtained through jigging separation test, both overall and each stage′s quality efficiencies of the jigging machine are calculated and briefly analyzed. Analysis result shows that the quality efficiency should be evaluated from the perspective of both floats and sinks; and for jigging separation of sinks, a higher quality efficiency can be obtained as compared with that of separation of floats, and the quality efficiency of the jig′s first stage is higher than that of its second-stage. It well demonstrates the applicability of the proposed indicator in jigging separation of coal and for evaluation of performance of this process.